The invention is directed to a corona ignition device for igniting fuel in a combustion chamber of an engine by a corona discharge, as is generally known from DE 10 2010 055 570 B3.
Corona ignition devices comprise a center electrode, which is held in an insulator and is thereby electrically insulated against a housing and the walls of the combustion chamber, which are at ground potential. The center electrode and a coil connected thereto form a capacitance together with the surrounding housing. This capacitance and the coil form an electric oscillating circuit, which is excited with a high frequency voltage, which is generated, for example, with the aid of a transformer having a center tap or another high frequency generator, and which typically has a frequency between 30 kHz and 3 MHz. When the oscillating circuit undergoes resonant excitation, a voltage spike occurs between the center electrode and the walls of the combustion chamber or the housing of the corona ignition device. This causes a corona discharge to form in the combustion chamber, said corona discharge originating from an ignition tip on the center electrode. This generates so many ions and radicals in the combustion chamber that the fuel-air mixture ignites.